The prosthetic treatment with dental implants is challenging in posterior maxilla, where there is a sinus pneumatization. For the rehabilitation of patients with intermediate bone level, short implants have been used as alternative. It is also needed to look for the prosthetic context of rehabilitation with implants, like the use of different materials as abutments. The aim of this study is to compare the survival of two sizes of implants (short vs standard) placed in upper premolars region with need of bone graft, with a minimum of three years of follow-up, and assess the behavior of different abutments (titanium vs zirconia) in prosthesis in this context. This will be a randomized clinical trial with two groups: 1) standard implants and sinus lift; and 2) short implants without sinus lift. The patients who fulfill the inclusion criteria and accept to participate of this study, will be included in the randomization process. At the implant installation, a brown envelope, with the word SHORT or STANDARD, will be open, in order to determine the group. Abutment type will be also randomized. Four months after the installation, torque will be confirmed and the abutment will be installed. Implant failure and prosthesis failure in function of the abutment will be the outcomes. Data analysis will be conducted following a previously established spreadsheet using the Kaplan-Meier method and log rank test for success and survival, followed by Cox regression, if possible and according to the number of failures.

Inclusion Criteria:

• good general and dental health;
• minimum of 6 mm bone width (BP);
• bone height in sinus region between 5 and 9 mm;
• bilateral posterior occlusal contact.

Exclusion Criteria:

• removable or partial denture;
• patient with systemic disease treatment in course;
• pregnant women;
• recent extraction at the site to receive the implant.